Gas turbines used as propulsion units in aircrafts, for example, usually include a plurality of rotating blades arranged in series in the axial direction of the gas turbine. The rotating blades are surrounded by a stationary housing. A gap, which should have the smallest possible dimensions to avoid gas turbine efficiency losses, is formed between the rotating blades and the housing.
The rotating blades and the stationary housing have different temperature variations over time. Thus, as heat is generated during operation of the gas turbine, in particular in non-steady-state operation of the gas turbine, the rotating blades and the stationary housing expand to different degrees. This may result in enlargement of the gap between the rotating blades and the housing.
In rotating equipment, such as gas turbines, the different degrees of expansion of stationary units and rotating units should be compensated. This may be achieved by improving the heat transfer between the stationary units and the rotating units. Improved heat transfer between the stationary units and the rotating units equalizes the temperature variations over time and heat absorption, and thus ultimately the expansion of stationary and rotating units. For gas turbines this would mean that the rotating blades and housing expand equally or evenly even during non-steady-state operation of the gas turbine, whereby the size of the gap between the rotating blades and the housing is ideally no longer subject to fluctuations.